TW202401486A - Multi-charge particle beam drawing device and multi-charge particle beam drawing method capable of avoiding unnecessary defect corrections when correcting an excessive dose caused by a defective beam across multiple drawing paths in multi-beam drawing - Google Patents

Abstract

The present invention provides a multi-charge particle beam drawing device and a multi-charge particle beam drawing method capable of avoiding unnecessary defect corrections when correcting an excessive dose caused by a defective beam across multiple drawing paths in multi-beam drawing. A multi-charge particle beam drawing device according to an embodiment of the present invention includes: a beam forming mechanism configured to form a multi-charge particle beam; a dose data generating unit configured to generate, for each of a plurality of processing areas into which a drawing area on a sample surface is divided, a dose data defined as an individual dose at each position within the processing area; a dose determination unit that determines, for each processing area, whether or not a position at which a dose of a value other than zero is defined is present in a vicinity including a defective position to be irradiated with a defective beam that leads to an excessive dose among the multi-charge particle beams; a defective position dose data generating unit that generates a defective dose data in which the defective dose is defined at the defective position when the dose having a value other than zero is defined in the vicinity; a pattern presence determination unit that determines, for each unit area on the sample surface which is set as an irradiation area of the multi-charge particle beam, presence of a pattern in the unit area by using dose data at each position to be irradiated in the unit area; and a drawing mechanism configured to, when using the multi-charge particle beam to draw a pattern on a sample, skip the unit area which is determined to have no pattern by the pattern presence determination unit and move a unit area where a drawing process is performed to the next area determined to have the pattern, and configured to correct an excessive dose caused by the defective beam in any one of a plurality of drawing paths in multiple drawing so as to reduce the excessive dose in another drawing path.

Description

Multi-charged particle beam drawing device and multi-charged particle beam drawing method

One aspect of the present invention relates to a multi-charged particle beam drawing device and a multi-charged particle beam drawing method, for example, to a method of reducing dimensional deviation of a pattern caused by multi-beam drawing.

Lithography technology, which is responsible for the advancement of miniaturization of semiconductor devices, is an extremely important process for generating unique patterns in the semiconductor manufacturing process. In recent years, with the high integration of LSI, the circuit line width required by semiconductor devices has been refined year by year. Here, electron beam (electron beam) drawing technology essentially has good resolution, and electron beams are used to draw mask patterns on mask substrates (Mask Blanks).

For example, there are drawing devices using multiple beams. Compared with the case of drawing with one electron beam, by using multiple beams, the processing capability of irradiating a plurality of beams at one time can be greatly improved. In such a multi-beam type drawing device, for example, electron beams emitted from an electron gun are passed through a mask having a plurality of holes to form multiple beams, and each of the unshielded beams is controlled by blanking. The mask image is reduced by the optical system, and is deflected by the deflector to illuminate the desired position on the sample.

Multi-beam mapping controls the dose irradiated from each beam according to the irradiation time. However, if the irradiation time control becomes difficult due to a malfunction of the blanking control mechanism, etc., a defective beam in which the beam is excessively irradiated may occur. When the necessary dose is not irradiated to the sample, there is a problem that a shape error occurs in the pattern formed on the sample. To deal with such a problem, a technology has been proposed to correct the excess dose by sharing it among a plurality of surrounding beams.

Although it has not yet been made public, technology for correcting excess doses caused by irradiation of defective beams across multiple drawing paths is being reviewed. On the other hand, in multi-beam imaging, for example, the imaging is performed while staggering the rectangular regions irradiated with multiple beams on the imaging region of the sample. In this case, in order to shorten the drawing time for a rectangular area in which a pattern does not exist, it is also desirable to skip the drawing process of such a rectangular area.

However, when the excess dose caused by the defective beam is corrected across multiple drawing paths, the rectangular area including the position where the defective beam is irradiated in a part of the drawing path may have no pattern. Dose data are generated independently between traced paths. In this case, for example, in the first drawing pass, the data is generated on the premise that the position irradiated with the defective beam in the second drawing pass is corrected. However, it may happen that the rectangular area including the position where the defective beam is irradiated becomes an area without a pattern in the second drawing path. In this case, if the drawing process of the patternless area is skipped, the defective beam that should be irradiated in the second drawing path is not irradiated, and the correction of the first drawing path is disintegrated. As a result, there are issues with unnecessary bug fixes being implemented.

One aspect of the present invention is to provide a multi-beam drawing apparatus and a multi-charged particle beam drawing apparatus that can avoid unnecessary defect correction when correcting an excess dose caused by a defective beam across drawing paths of the multi-beam drawing. Particle beam mapping methods.

A multi-charged particle beam drawing apparatus according to one aspect of the present invention includes: a beam forming mechanism that forms a multi-charged particle beam; a dose data generating unit that generates dose data defining individual doses for each position within the processing area for each of a plurality of processing areas divided by the drawing area on the sample surface; A dose determination unit that determines, for each processing area, whether there is a location where a dose defining a non-zero value exists in an area including a predetermined defect location that forms a defective beam with an excess dose among the irradiated multi-charged particle beams. ; a defective position dose data generating unit that generates defective dose data in which a defective dose is defined at the defective position when a dose of a non-zero value is defined in a nearby area; A pattern presence/absence determination unit determines the pattern in the unit area for each unit area on the sample surface where the multi-charged particle beam irradiation area is set, using dose data at each position scheduled for irradiation in the unit area. the presence or absence of; and A drawing mechanism that uses a multi-charged particle beam to draw a pattern on a sample by skipping the unit area judged as having no pattern by the pattern presence/absence judgment unit, and moving the drawing process to the next unit area judged as having a pattern. By moving the unit area, the excess dose caused by the defective beam in any one of the plural drawing paths of the multi-drawing is corrected so that it is reduced in the other drawing paths.

Also, it has: A movable platform for carrying specimens; and Tracking deflector, which tracks the multi-charged particle beam in such a way that the irradiation area of the multi-charged particle beam follows the movement of the platform. The unit area is set appropriately for each tracking control due to tracking bias.

In addition, the pattern presence/absence determination unit determines that the presence of the pattern in each unit area is appropriate.

Or, it further includes: a memory device that stores the determination result of the presence or absence of the pattern for each unit area,

In the second and subsequent drawing paths of the plural drawing paths of the multi-drawing, based on the determination result of the presence or absence of the pattern per unit area in the previous path, it is determined whether it is appropriate to correct the excess dose caused by the defective beam in that path. .

In addition, the determination of the presence or absence of patterns per unit area is preferably performed as preprocessing before starting the drawing process.

One aspect of the multi-charged particle beam drawing method of the present invention includes: The process of forming a multi-charged particle beam; The process of generating dose data defining individual doses at each position within the treatment area for each of a plurality of treatment areas divided by the drawing area on the sample surface; A process of determining, for each processing area, whether there is a position where a dose defining a non-zero value exists in an area including a predetermined defect position that forms a defective beam with an excess dose among the irradiated multi-charged particle beams; A process of generating defect dose data in which a defect dose is defined at a defect position when a dose with a non-zero value is defined in a nearby area; A process for determining the presence or absence of a pattern in the unit area using dose data at each position scheduled for irradiation of the unit area for each unit area on the sample surface where the multi-charged particle beam irradiation area is set; and A multi-charged particle beam is used to draw a pattern on the sample. When drawing, the unit area judged to be without a pattern is skipped, and the unit area to be drawn is moved to the next unit area judged to be patterned. The excess dose caused by the defective beam in any one of the plurality of drawing paths is corrected to a process of reducing it in the other drawing paths.

Furthermore, the method further includes: a process of tracking the multi-charged particle beam so that the irradiation area of the multi-charged particle beam can follow the movement of the movable platform on which the sample is placed, The unit area is set appropriately for each tracking control due to tracking bias. According to one aspect of the present invention, in multi-beam drawing, unnecessary defect correction can be avoided when correcting excess doses caused by defective beams across drawing paths of multiple drawings.

Hereinafter, in the embodiment, a configuration using an electron beam will be described as an example of a charged particle beam. However, the charged particle beam is not limited to the electron beam, and a charged particle beam such as an ion beam may be used. Embodiment 1

FIG. 1 is a conceptual diagram showing the structure of a drawing device according to Embodiment 1. In FIG. 1 , the drawing device 100 includes a drawing mechanism 150 and a control circuit 160 . The drawing device 100 is an example of a multi-charged particle beam drawing device. The drawing mechanism 150 includes an electron column 102 (multiple electron beam arrays) and a drawing chamber 103 . The electron barrel 102 is configured with an electron gun 201, an illumination lens 202, a shaped aperture array substrate 203, a blanking aperture array (Blanking Aperture Array) mechanism 204, a reducing lens 205, a total blanking deflector 212, a limiting aperture substrate 206, Objective lens 207, deflector 208 and deflector 209. An XY stage 105 is arranged in the drawing room 103 . On the XY stage 105 is a sample 101 on which a photoresist-coated mask substrate, which becomes a substrate to be drawn during drawing, and the like are arranged. The sample 101 includes an exposure mask when manufacturing a semiconductor device, a semiconductor substrate (silicon wafer) on which a semiconductor device is manufactured, and the like. Further, a mirror 210 for position measurement of the XY stage 105 is disposed on the XY stage 105 . The XY platform 105 is further equipped with a Faraday cup 106.

The control system circuit 160 is a memory device 140 including a control computer 110, a memory 112, a bias control circuit 130, digital-to-analog conversion (DAC) amplifier units 132, 134, 136, a platform position detector 139, a disk device, and the like. ,142,144. The control computer 110, memory 112, bias control circuit 130, DAC amplifier units 132, 134, 136, platform position detector 139 and memory devices 140, 142, 144 are connected to each other via a bus (not shown). The bias control circuit 130 is connected to the DAC amplifier units 132, 134, 136 and the blanking aperture array mechanism 204. The output of DAC amplifier unit 132 is connected to deflector 209 . The output of DAC amplifier unit 134 is connected to deflector 208 . The output of DAC amplifier unit 136 is connected to master blanking deflector 212 . The deflector 208 is composed of four or more electrodes, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 134 . The deflector 209 is composed of four or more electrodes, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 132 . The total blanking deflector 212 is composed of two or more electrodes, and each electrode is controlled by the deflection control circuit 130 via the DAC amplifier 136 .

The stage position detector 139 irradiates laser light to the reflecting mirror 210 on the XY stage 105 and receives the reflected light from the reflecting mirror 210 . Then, the position of the XY stage 105 is measured using the principle of laser interference using such reflected light information.

The control computer 110 is provided with a rasterizing unit 50, a dose data generating unit 52, a beam position deviation map generating unit 54, a position deviation correcting unit 56, a measuring unit 57, a specifying unit 58, and a defect. Correction unit 60 , limited dose determination unit 62 , defect dose data creation unit 64 , irradiation time calculation unit 66 , data processing unit 67 , NULL determination unit 68 and drawing control unit 74 . Rasterization unit 50, dose data creation unit 52, beam position deviation map creation unit 54, position deviation correction unit 56, detection unit 57, identification unit 58, defect correction unit 60, limited dose determination unit 62, defect Each "~ section" such as the dose data creation section 64, the irradiation time calculation section 66, the data processing section 67, the NULL determination section 68, and the drawing control section 74 has a processing circuit. Such processing circuits include, for example, electrical circuits, computers, processors, circuit substrates, quantum circuits or semiconductor devices. Each "~ section" may use a common processing circuit (same processing circuit), or may use different processing circuits (separate processing circuits). It is input to the rasterization unit 50, the dose data creation unit 52, the beam position deviation map creation unit 54, the position deviation correction unit 56, the detection unit 57, the identification unit 58, the defect correction unit 60, and the limited dose determination unit. The information of the unit 62, the defect dose data creation unit 64, the irradiation time calculation unit 66, the data processing unit 67, the NULL determination unit 68 and the drawing control unit 74 and the information being calculated are stored in the memory 112 each time.

Furthermore, rendering data is input from outside the rendering device 100 and stored in the memory device 140 . The drawing data usually defines information that defines plural graphic patterns for drawing. Specifically, the graphic code, coordinates, size, etc. are defined for each graphic pattern.

Here, the configuration necessary for explaining Embodiment 1 is shown in FIG. 1 . The rendering device 100 may be provided with other generally necessary configurations.

FIG. 2 is a conceptual diagram showing the structure of the molded aperture array substrate according to the first embodiment.

In FIG. 2 , the formed aperture array substrate 203 has p rows in the vertical direction (y direction) and q rows in the transverse direction (x direction) (p, q≧2). The holes (openings) 22 are formed in a matrix with a predetermined arrangement pitch. In FIG. 2 , for example, 512×512 rows of holes 22 are formed vertically and horizontally (x, y directions). Each hole 22 is formed in a rectangular shape with the same size. Or, even a circle with the same diameter is fine. The shaped aperture array substrate 203 (beam forming mechanism) forms multiple beams 20 . Specifically, a part of the electron beam 200 passes through the plurality of holes 22 to form the multiple beams 20 . In addition, the arrangement method of the holes 22 is not limited to the case where the holes 22 are arranged vertically and horizontally in a grid shape as shown in FIG. 2 . For example, the holes in the k-th row in the longitudinal direction (y direction) and the k+1-th row may be arranged offset from each other by only the dimension a in the transverse direction (x direction). Similarly, the holes of the k+1th row in the longitudinal direction (y direction) and the k+2th row may be arranged offset from each other by only the dimension b in the transverse direction (x direction).

3 is a cross-sectional view showing the structure of the blanking aperture array mechanism according to the first embodiment. As shown in FIG. 3 , the blanking aperture array mechanism 204 has a semiconductor substrate 31 made of silicon or the like placed on a support base 33 . The central portion of the substrate 31 is a thin film region 330 (first region) that is cut off from the back side and processed to have a thin film thickness h, for example. Surrounding the thin film region 330 is an outer peripheral region 332 (second region) having a thick film thickness H. The upper surface of the thin film region 330 and the upper surface of the outer peripheral region 332 are formed at the same height position or substantially the same height position. The substrate 31 is held on the support base 33 on the back surface of the outer peripheral area 332 . The central portion of the support base 33 is an opening, and the film region 330 is located in an area of the opening of the support base 33 .

In the thin film region 330 , passage holes 25 (openings) for passing the respective beams of the multiple beams 20 are opened at positions corresponding to the respective holes 22 of the molded aperture array substrate 203 shown in FIG. 2 . In other words, a plurality of through holes 25 through which corresponding beams of the plurality of beams 20 using electron beams pass pass are formed in an array in the thin film region 330 of the substrate 31 . Furthermore, on the thin film region 330 of the substrate 31 , a plurality of electrode pairs each having two electrodes are arranged at positions facing each other across the respective through holes 25 . Specifically, as shown in FIG. 3 , in the thin film region 330 , the control electrode 24 for blanking bias and the counter electrode 26 are respectively arranged in the vicinity of each through hole 25 with the corresponding through hole 25 interposed therebetween. Group (blanking device: blanking deflector: 1st deflector). Furthermore, inside the substrate 31 , a control circuit 41 (logic circuit) for applying a bias voltage to the control electrode 24 for each through hole 25 is arranged near each through hole 25 in the thin film region 330 . The counter electrode 26 for each beam is connected to the ground.

An amplifier (not shown) (an example of a switching circuit) is arranged within the control circuit 41 . A CMOS (Complementary MOS) inverter circuit is configured as an example of an amplifier. Furthermore, the CMOS converter circuit is connected to a positive potential (Vdd: blanking potential: first potential) (for example, 5V) (first potential) and a ground potential (GND: second potential). The output line (OUT) of the CMOS converter circuit is connected to the control electrode 24 . On the other hand, the counter electrode 26 is applied with a ground potential. Furthermore, a plurality of control electrodes 24 to which a blanking potential and a ground potential can be applied switchably are arranged on the substrate 31 via corresponding through holes 25 of the plurality of through holes 25 and connected to the plurality of counter electrodes 26 . or the position where the corresponding counter electrode 26 faces.

The input (IN) of the CMOS converter circuit is controlled by applying either an L (low) potential lower than the threshold voltage (for example, ground potential) or an H (high) potential above the threshold voltage (for example, 1.5V). signal. In Embodiment 1, in a state where L potential is applied to the input (IN) of the CMOS converter circuit, the output (OUT) of the CMOS converter circuit becomes a positive potential (Vdd), and is connected to the ground potential of the counter electrode 26 The electric field caused by the potential difference deflects a corresponding one of the multiple beams 20 to limit the shielding of the aperture substrate 206, thereby controlling the beam to be OFF. On the other hand, when the H potential is applied to the input (IN) of the CMOS converter circuit (active state), the output (OUT) of the CMOS converter circuit becomes the ground potential, and the potential difference from the ground potential of the counter electrode 26 is eliminated. , since the corresponding one of the plurality of beams 20 is not deflected, the limiting aperture substrate 206 is used to control the beam to be ON.

A corresponding electron beam among the multiple beams 20 passing through each passage hole is deflected by a voltage applied to two independent pairs of control electrodes 24 and counter electrodes 26 . Blanking control is achieved by such a bias. Specifically, the set of the control electrode 24 and the counter electrode 26 individually blanks and deflects the corresponding beam of the multi-beam 20 based on the potential switched by the corresponding CMOS converter circuit serving as a switching circuit. . In this way, the plurality of blanking devices perform blanking deflection of corresponding beams among the plurality of beams 20 passing through the plurality of holes 22 (openings) of the shaped aperture array substrate 203 .

FIG. 4 is a conceptual diagram for explaining an example of the drawing operation in Embodiment 1. FIG. As shown in FIG. 4 , the drawing area 30 (thick line) of the sample 101 is, for example, a plurality of strip areas 32 divided into rectangular shapes with a predetermined width toward the y direction.

In the example of FIG. 4 , the first stripe layer is set to be composed of a plurality of stripe regions 32 obtained by dividing the drawing area 30 . Furthermore, a second stripe layer is set, which is composed of a plurality of stripe regions 32 whose positions are shifted in the y direction by half the width of the stripe region 32 with respect to the first stripe layer. Thus, in the example of FIG. 4 , two stripe-shaped layers are provided, namely, the first stripe-shaped layer and the second stripe-shaped layer. Therefore, by combining the first stripe-shaped layer and the second stripe-shaped layer, a plurality of stripe-shaped regions 32 partially overlapped in the y direction are set. The example in FIG. 4 shows a case where strip-shaped areas 32 adjacent to each other in the y direction overlap each other by 1/2 of the area. Furthermore, it is appropriate to provide one more stripe area 32 in the second stripe layer from the end of the drawing area 30 in the −y direction. Next, an example of the drawing operation will be described.

First, the XY stage 105 is moved and adjusted so that the irradiation area 34 of the multi-beam 20 is located at the left end or a position further to the left of the first strip area 32 of the second strip layer. Then, the first stripe area 32 of the second stripe layer is drawn. When drawing the first stripe region 32 of the second stripe layer, the XY stage 105 is moved to the -x direction, for example, so that the drawing is relatively advanced in the x direction. The XY stage 105 is continuously moved at a constant speed, for example. After the drawing of the first stripe area 32 of the second stripe layer is completed, the platform position is shifted to the −y direction by an amount equal to half the width of the stripe area 32 .

Then, secondly, the irradiation area 34 of the multi-beam 20 is adjusted to be located at the right end or a right side of the first strip area 32 of the first strip layer. Then, by moving the XY stage 105 to, for example, the x direction, drawing is relatively advanced in the -x direction. Thereby, the first stripe area 32 of the first stripe layer is drawn. After the drawing of the first stripe area 32 of the first stripe layer is completed, the drawing of the second stripe area 32 of the second stripe layer is performed. By alternately drawing the first stripe layer and the second stripe layer, multiple drawings are performed at each position. In addition, the above-mentioned example shows the case of drawing while alternately changing the direction. However, the present invention is not limited to this. When drawing each stripe area 32, the drawing may be advanced in the same direction.

FIG. 5 is a diagram showing an example of a multi-beam irradiation area and drawing target pixels according to the first embodiment. In FIG. 5 , for example, a plurality of control grids (grid) 27 (design grid) arranged in a grid shape at the beam size pitch of the plurality of beams 20 on the surface of the sample 101 are set in the stripe area 32 . It is suitable that the control grid 27 has an arrangement pitch of about 10 nm, for example. Such a plurality of control grids 27 serve as the designed irradiation positions of the multi-beam 20 . The arrangement pitch of the control grid 27 is not limited to the beam size, and may be configured with any size that can control the deflection position of the deflector 209 regardless of the beam size. Then, a plurality of pixels 36 are virtually divided into a grid shape with each control grid 27 as the center and having the same size as the arrangement pitch of the control grid 27 . Each pixel 36 is an irradiation unit area for each beam of the plurality of beams. The example in FIG. 5 shows that the drawing area of the sample 101 is substantially the same width in the y direction as the size of the irradiation area 34 (drawing field) that can be irradiated by one irradiation of the multi-beam 20 (beam array). The case is divided into a plurality of strip areas 32 according to the size. The x-direction size of the irradiation area 34 can be defined by multiplying the inter-beam spacing in the x-direction of the multiple beams 20 by the number of beams in the x-direction. The y-direction size of the irradiation area 34 can be defined by multiplying the inter-beam spacing in the y-direction of the multiple beams 20 by the number of beams in the y-direction. In addition, the width of the strip area 32 is not limited to this. A size that is n times (n is an integer greater than 1) of the irradiation area 34 is appropriate. In the example of FIG. 5 , for example, the illustration of the multi-beam in 512×512 columns is omitted to represent the multi-beam in 8×8 columns. Furthermore, a plurality of pixels 28 (beam drawing positions) that can be irradiated by one emission of the plurality of beams 20 in the irradiation area 34 are shown. In other words, the spacing between adjacent pixels 28 becomes the designed spacing between the multiple beams. In the example of FIG. 5 , one sub-irradiation area 29 is constituted by an area surrounded by the pitch between beams. The example in FIG. 5 shows a case where each sub-irradiation area 29 is composed of 4×4 pixels.

FIG. 6 is a diagram for explaining an example of the multi-beam drawing method according to the first embodiment. In FIG. 6 , the coordinates (1,3), (2,3), (3,3), and ･ of the k-th segment in the y direction among the multiple beams depicting the strip area 32 shown in FIG. 5 are shown. A part of the sub-irradiation area 29 drawn by each beam of ･･, (512,3). The example in FIG. 6 shows a case where, for example, four pixels are drawn (exposed) while the XY stage 105 is moved by a distance of 8 beam pitches. During such drawing (exposure) of four pixels, the entire multi-beam 20 is directed by the deflector 208 so that the relative position of the irradiation area 34 to the sample 101 does not shift due to the movement of the XY stage 105. Total bias. Thereby, the irradiation area 34 follows the movement of the XY stage 105 . In other words, track and control. The deflector 208 will serve as a tracking deflector to perform tracking deflection of the multiple beams 20 so that the irradiation area 34 of the multiple beams 20 can follow the movement of the platform. The example in FIG. 6 shows a case where one tracking cycle is performed by drawing (exposing) four pixels while moving a distance of eight beam pitches.

Specifically, in each emission, a beam corresponding to the drawing time (irradiation time or exposure time) of the control grid 27 corresponding to the set maximum drawing time is irradiated. Specifically, each control grid 27 is irradiated with a beam corresponding to each of the ON beams among the plurality of beams 20 . Then, the irradiation position of each beam is moved toward the next emission position by the total deflection caused by the deflector 209 for each emission cycle time Ttr which is the maximum drawing time plus the settling time of the DAC amplifier.

Then, in the example of FIG. 6 , the DAC amplifier unit 134 resets the beam deflection for tracking control at the time point of completion of the 4 transmission. Thereby, the tracking position is returned to the tracking start position where tracking control is started.

In addition, the drawing of the first pixel column from the right of each sub-irradiation area 29 is completed. Therefore, after the tracking is reset, in the next tracking cycle, first the deflector 209 is deflected (shifted) to correspond to the first segment from the bottom and the second segment from the right of each sub-irradiation area 29 . The pixels control the drawing position of the beam on the grid 27 . By repeating this action, all pixels are drawn. When the sub-irradiation area 29 is composed of n×n pixels, each n pixel is drawn with a different beam in n times of tracking operations. With this, all pixels in an area of n×n pixels are drawn. The same operation is performed on other n×n pixel areas within the multi-beam irradiation area at the same time and is drawn in the same manner.

By such an operation, as shown in the irradiation areas 34a to 34o in FIG. 4 , the irradiation area 34 moves on the strip area 32 while drawing according to the platform movement amount of one tracking control, for example, 8 beam pitches each. Process forward.

Next, the operation of the drawing mechanism 150 of the drawing device 100 will be described. The electron beam 200 emitted from the electron gun 201 (emission source) illuminates the entire shaped aperture array substrate 203 through the illumination lens 202 . A plurality of rectangular holes 22 (openings) are formed in the formed aperture array substrate 203 . The electron beam 200 then illuminates all areas containing the plurality of holes 22 . Parts of the electron beams 200 irradiated at the positions of the plurality of holes 22 respectively pass through the plurality of holes 22 of the aperture array substrate 203 thus formed. Thereby, a plurality of electron beams (multiple beams 20 ) in a rectangular shape, for example, are formed. Such multiple beams 20 pass through corresponding blanking devices (first deflectors) of the blanking aperture array mechanism 204 . Such a blanking device deflects individual passing electron beams (performs blanking deflection).

The multiple beams 20 passing through the blanking aperture array mechanism 204 are reduced by the reduction lens 205 and advance toward the hole formed in the center of the limiting aperture substrate 206 . Here, among the multiple beams 20 , the electron beams deflected by the blanking device of the blanking aperture array mechanism 204 are positioned away from the hole in the center of the limiting aperture substrate 206 and are shielded by the limiting aperture substrate 206 . On the other hand, the electron beams that are not deflected by the blanking device of the blanking aperture array mechanism 204 pass through the hole in the center of the limiting aperture substrate 206 as shown in FIG. 1 . Blanking control is performed by turning ON/OFF of such a blanking device, and the ON/OFF of the beam is controlled. In this manner, the limiting aperture substrate 206 blocks each beam that is deflected into a beam OFF state by the blanking device. Then, for each beam, a beam that is emitted once is formed by the beam that passes through the limiting aperture substrate 206 after the beam formation is ON until the beam formation is OFF. The multiple beams 20 that pass through the limited aperture substrate 206 are focused by the object lens 207 to form a pattern image with a desired reduction ratio. Each beam that passes through the limited aperture substrate 206 (the entire multi-beam 20 that passes through it) is The deflectors 208 and 209 are collectively deflected in the same direction, and are irradiated to respective irradiation positions on the sample 101 of each beam. The multiple beams 20 irradiated at once are ideally arranged so that the arrangement pitch of the plurality of holes 22 of the formed aperture array substrate 203 is multiplied by the pitch of the desired reduction rate mentioned above.

As mentioned above, defective beams will be generated in multiple beams. A defective beam can be an over-dose defective beam in which the dose of the beam cannot be controlled and the irradiated dose is excessive, and an under-dose defective beam in which the dose of the beam cannot be controlled and the irradiated dose is insufficient. The excessive dose defective beam includes an ON defective beam that always turns ON and a part of a poorly controlled defective beam that has poor irradiation time control. Insufficient dose defective bundles include OFF defective bundles that are always turned OFF and remaining portions of control-poor defective bundles.

When a dose more than a predetermined dose is irradiated to the sample due to a defective beam, there is a problem that a shape error occurs in the pattern formed on the sample. For such problems, defect correction is performed to offset the excess dose. In Embodiment 1, multiple drawing is performed in which drawing processing is performed using a plurality of drawing paths. Then, such defect correction is performed on a drawing path different from the drawing path of the irradiated defective beam. On the other hand, in multi-beam imaging, for example, the rectangular region (an example of a unit region) irradiated with the multi-beam 20 is advanced while shifting the imaging region of the sample 101 . The rectangular area (beam array area) here is a multi-beam that forms each sub-irradiation area 29 (small area) surrounded by each beam of the combined multi-beam 20 and other adjacent plural beams. irradiation area 34. In addition, the unit area is not limited to a rectangular shape. The shape of the unit area may be another shape according to the arrangement shape of the multiple beams.

In the example of FIG. 4 , the irradiation area 34 is moved by, for example, 8 beam pitches each tracking period, and the rectangular areas irradiated with the multiple beams 20 on the strip area 32 are shifted by 8 beam pitches while overlapping. For example, the first pixel row from the right of each sub-irradiation area 29 in the rectangular area corresponding to the irradiation area 34a becomes the irradiation target. For example, in the rectangular area corresponding to the irradiation area 34b, two pixel columns from the right of each sub-irradiation area 29 become the irradiation targets. For example, the third pixel row from the right of each sub-irradiation area 29 in the rectangular area corresponding to the irradiation area 34c becomes the irradiation target. For example, the fourth pixel row from the right of each sub-irradiation area 29 in the rectangular area corresponding to the irradiation area 34d becomes the irradiation target. In subsequent rectangular areas, the irradiation target pixels will be similarly shifted. In this case, in order to shorten the drawing time for a rectangular area in which a pattern does not exist in the irradiation target pixel, it is also desirable to adjust the drawing process of such a rectangular area.

In addition, when skipping the drawing process of the rectangular area, during the skip operation, the multiple beams 20 are all deflected by the total blanking deflector 212, thereby using the limited aperture substrate 206 to shield the defective beam 11 A total of 20 multi-beams are enough.

FIG. 7 is a diagram showing an example of the presence or absence of patterns in each drawing path according to Embodiment 1. FIG. In FIG. 7 , the pattern 12 is arranged in the rectangular area 13 where certain tracking control is performed in the first drawing path (first path). Such a rectangular area 13 includes a position where the defective beam 11 is irradiated in the second drawing path (second path). The position of the irradiated defective beam 11 on the first path is not shown in the figure.

Furthermore, when creating dose data for irradiating the rectangular area 13 along the first path, the data is generated on the premise of performing defect correction that corrects the excess dose caused by the defective beam 11 being irradiated along the second path. . Furthermore, the position where the defective beam 11 is irradiated in the second path is included in the rectangular area 13 where certain tracking control is performed. Here, the rectangular area 13 including the position where the defective beam 11 is irradiated in the second path may form a patternless area as shown in FIG. 7 . In this way, when the excess dose caused by the defective beam is corrected across multiple drawing paths, the rectangular area 13 including the position where the defective beam is irradiated in part of the drawing paths may have no pattern. Dose data are generated independently between traced paths. In this case, if the drawing process of the patternless rectangular area 13 is skipped in the second drawing path, the defective beam 11 will not be irradiated, and the premise of the correction in the first drawing path will be destroyed. As a result, there are issues with unnecessary bug fixes being implemented.

On the contrary, the rectangular area 13 in the second path includes the position where the defective beam was irradiated in the first path. When creating the dose data for irradiating the rectangular area 13 of the second path, the data is generated on the premise of performing defect correction to correct the excess dose caused by the defective beam 11 being irradiated on the first path. However, it is possible that a patternless area is formed in the rectangular area including the position where the defective beam is irradiated in the first path. If the drawing process of the patternless rectangular area is skipped in the first drawing path, the defective beam will not be irradiated, and the premise of correction in the second drawing path will be broken down. As a result, there are issues with unnecessary bug fixes being implemented.

Therefore, in Embodiment 1, when a pixel having a dose of a defined non-zero value (limited value) in design exists around the position where the defective beam is irradiated, even if the rectangular area 13 subject to tracking control has no pattern, Don't skip.

For example, when a defective beam is irradiated in the drawing process of the first path, a patternless area may be formed in the rectangular area 13 of the irradiation target in the second path at the position irradiated with the defective beam in the first path. If the originally designed pattern does not exist around the defective beam, there will be no shape error caused by the pattern of the defective beam. Therefore, in this case, the defective bundle can be ignored, so there is no problem even if the drawing process is skipped.

FIG. 8 is a flowchart showing the main steps of the drawing method according to the first embodiment. In FIG. 8 , the drawing method according to Embodiment 1 implements a beam position deviation measurement step (S102), a defective beam detection step (S104), a dose calculation step (S110), and a position deviation correction step for each path. (S112), defective beam position identification process for each path (S120), defective beam correction process (S122), defective vicinity limited dose determination process (S130), defective dose data creation process (S132), irradiation time calculation process (S142) ), a data processing step (S144), a main deflection data NULL determination step (S146), and a series of steps including a drawing step (S150).

Defect beam correction process (S122), defect vicinity limited dose determination process (S130), defect dose data creation process (S132), irradiation time calculation process (S142), data processing process (S144), main deflection data NULL determination process (S146) ) and the drawing process (S150) are performed for each drawing path.

The drawing device 100 measures the positional deviation amount of the irradiation position on the surface of the sample 101 of each beam of the plurality of beams 20 from the corresponding control grid 27 as a beam position deviation measuring step (S102).

FIG. 9 is a diagram for explaining the position shift and position shift periodicity of the beam in Embodiment 1. FIG. As shown in FIG. 9(a) , the multi-beam 20 deforms the exposure field due to the characteristics of the optical system. Due to such deformation, the actual irradiation position 39 of each beam changes from the ideal grid irradiation position. In the case of grid, the irradiation position 37 is shifted. Therefore, in Embodiment 1, the positional deviation amount of the actual irradiation position 39 of each beam is measured. Specifically, a position measuring device is used to measure the position of the photoresist pattern produced by irradiating the evaluation substrate coated with the photoresist with the multiple beams 20 and developing the evaluation substrate. Thereby, the positional offset of each beam is measured. As for the emission size of each beam, if it is difficult to measure the size of the photoresist pattern at the irradiation position of each beam with a position measuring device, a pattern pattern of a size that can be measured with a position measuring device is drawn with each beam (for example, rectangular pattern). Then, just measure the edge positions on both sides of the graphic pattern (photoresist pattern), and measure the positional deviation amount of the target beam based on the difference between the middle position between the two edges and the designed middle position of the graphic pattern. Then, the obtained positional offset data of the irradiation position of each beam is input to the drawing device 100 and stored in the memory device 144 . In addition, since the multi-beam drawing advances the drawing within the bar-shaped area 32 while shifting the irradiation area 34, for example, the drawing sequence explained in FIG. 6 is as shown in the lower part of FIG. 4. During the drawing of the bar-shaped area 32 , the position of the irradiation area 34 will move in the order of the irradiation areas 34a to 34o. Then, every movement of the irradiation area 34 causes periodicity in the positional deviation of each beam. Alternatively, as long as each beam is in the drawing order of irradiating all the pixels 36 in each corresponding sub-irradiation area 29, as shown in FIG. 9(b), at least each unit of the same size as the irradiation area 34 In the area 35 (35a, 35b, ･･･), periodicity occurs in the positional deviation of each beam. Therefore, simply by measuring the positional deviation amount of each beam in the 34 irradiation areas of the beam array, the measurement results can be used. In other words, it suffices to measure the positional deviation amount of each pixel 36 in the corresponding sub-irradiation area 29 for each beam.

Then, the beam position deviation map creation unit 54 first creates a beam position deviation amount map (1) defined corresponding to the beam array unit, in other words, the irradiation area 34 The positional deviation amount of each beam of each pixel 36 in one rectangular unit area 35 on the sample surface. Specifically, the beam position deviation map creation unit 54 simply reads the position deviation data of the irradiation position of each beam from the memory device 144, and uses such data as the map value to create the beam position deviation map. (1) is enough. Which beam irradiates the control grid 27 of each pixel 36 in a rectangular unit area 35 on the sample surface corresponding to the entire irradiation area 34 of the multi-beam 20 depends on the drawing order as explained in FIG. 6 , for example. Depends. Therefore, the beam position shift map creation unit 54 specifies the beam responsible for irradiating the control grid 27 for each control grid 27 of each pixel 36 in the unit area 35 in the order of drawing, and Calculate the position offset of this beam. The created beam position offset map (1) is stored in the memory device 144 in advance.

The detection unit 57 detects defective beams from the plurality of beams 20 as a defective beam detection step (S104). The ON defective beam that always turns ON is a beam that is always irradiated once for the maximum irradiation time regardless of the dose control. Alternatively, the irradiation is continued during further movement between pixels. In addition, the OFF defective beam that always turns OFF is irrelevant to the control dose and always turns OFF. Specifically, under the control of the rendering control unit 74 , the rendering mechanism 150 is controlled so that each of the plurality of beams 20 forms a beam ON in the blanking aperture array mechanism 204 , and the remaining ones are controlled so that all the beams are formed. OFF. In such a state, a beam in which current is not detected in the Faraday cup 106 is detected as an OFF defective beam. On the contrary, the switching control is to turn OFF the target beam formation detected from such a state. At this time, although the beam is switched from beam ON to beam OFF, the beam in which the constant current is measured in the Faraday cup 106 is detected as an ON defective beam. After switching from beam ON to beam OFF, the beam whose current is measured in the Faraday cup 106 for only a predetermined period is detected as a control defective beam. As long as all the beams of the multi-beam 20 are sequentially checked in the same way, the presence or absence of the defective beam, the type and the position of the defective beam can be detected. Here, a case is described in which defective beams other than ON defective beams are also detected. However, it does not matter if only ON defective beams that are always turned ON are detected. The information of the detected defective beams is stored in the memory device 144 .

The dose data generating unit 52 (dose calculation unit) generates dose data defining individual doses for each position in the processing area for each of the plurality of processing areas divided by the drawing area on the surface of the sample 101. , as the dose calculation process (S110). Specifically, it operates as follows. First, the rasterizing unit 50 reads the drawing data from the memory device 140, and calculates the pattern area density ρ' in each pixel 36 for each pixel 36. Such processing is performed for each stripe area 32, for example.

Next, the dose data creation unit 52 first virtually divides the drawing area (for example, the stripe area 32 here) into a plurality of proximity grid areas (proximity effect correction calculation grid areas) in a grid-like manner with a predetermined size. . The size of the proximity grid area is appropriately set to about 1/10 of the influence range of the proximity effect, for example, about 1 μm. The dose map creation unit 62 reads the drawing data from the memory device 140 and calculates the pattern area density ρ of the pattern arranged in the close grid area for each close grid area.

Next, the dose data creation unit 52 calculates the proximity effect correction irradiation coefficient Dp(x) (corrected irradiation amount) for correcting the proximity effect for each proximity grid area. The unknown proximity effect corrected irradiation coefficient Dp(x) is the same proximity effect as the conventional method using the backscattering coefficient eta, the irradiation dose threshold Dth of the critical value model, the pattern area density ρ, and the distribution function g(x). The critical value model used for correction is defined.

Next, the dose data creation unit 52 calculates, for each pixel 36 , the incident irradiation amount D(x) (dose) used to irradiate the pixel 36 . The incident irradiation amount D(x) may be calculated as a value obtained by multiplying the preset reference irradiation amount Dbase by the proximity effect correction irradiation coefficient Dp and the pattern area density ρ', for example. The reference irradiation amount Dbase can be defined by, for example, Dth/(1/2+n). By the above, it is possible to obtain the originally expected incident irradiation amount D(x) with the proximity effect corrected based on the layout of the plural graphic patterns defined as the drawing data.

The dose data creation unit 52 performs the above-mentioned processing for each processing area divided into the stripe area 32 . For example, a rectangular unit area 35 having the same size as the irradiation area 34 can be used as the treatment area. Furthermore, the dose data creation unit 52 creates a dose map that defines the incident irradiation amount D(x) for each pixel 36 in processing area units. Such incident irradiation amount D(x) for each pixel 36 is designed to be a predetermined incident irradiation amount D(x) irradiated to the control grid 27 of the pixel 36 . The created dose map is stored in the memory device 144, for example.

The position shift correction unit 56 creates a dose map in which the individual position shift of each irradiation position of the multi-beam 20 is corrected for each drawing path, as a position shift correction step for each path (S112).

First, the dose for each pixel per drawn path is defined. Specifically, it operates as follows. The position shift correction unit 56 reads the dose map from the memory device 144, for example, and calculates the dose per drawing path in which the dose defined for each pixel is divided by the number of drawing paths. Next, positional shift correction of the beam irradiating each pixel is performed for each drawing path. Which beam irradiates which pixel in each path is determined based on the drawing order.

FIG. 10 is a diagram illustrating an example of the position offset correction method according to Embodiment 1. FIG. The example in Fig. 10(a) shows a case where the beam a' irradiated to the pixel at coordinates (x, y) causes a positional shift to the -x, -y side. In order to correct the positional shift of the pattern formed by the beam a' causing such a positional shift to a position consistent with the pixel of the coordinates (x, y) as shown in FIG. 10(b), it is possible to allocate The direction of the offset surrounding pixels is the pixel on the opposite side to correct the illumination amount of the offset part. In the example of FIG. 10(a) , the irradiation amount of the portion shifted to the pixel at the coordinates (x, y-1) only needs to be allocated to the pixel at the coordinates (x, y+1). The irradiation amount of the portion shifted to the pixel at the coordinates (x-1, y) only needs to be allocated to the pixel at the coordinates (x+1, y). The irradiation amount of the portion shifted to the pixel at the coordinates (x-1, y-1) only needs to be allocated to the pixel at the coordinates (x+1, y+1).

In Embodiment 1, the positional shift correction distribution amount of the beam is calculated in proportion to the positional shift amount of the beam for distributing the irradiation amount to at least one surrounding pixel. The position shift correction data creation unit 52 calculates the modulation rate of the beam directed to the pixel and the at least 10% modulation rate of the beam directed to the pixel in accordance with the ratio of the area shifted by the position shift of the beam directed to the pixel. Modulation rate of the beam of 1 pixel. Specifically, for each surrounding pixel where the beam is shifted from the pixel of interest and a part of the beam overlaps, the ratio of the area of the shifted portion (the area of the overlapping beam portion) divided by the beam area is calculated as the previous value. The distribution amount (modulation rate of the beam) of the pixels on the opposite side to the overlapping pixel with respect to the pixel of interest.

In the example of Figure 10(a), the area ratio of the pixel offset to the coordinates (x, y-1) can be shifted in the (x direction beam size - (-x) direction offset amount) × y direction Calculate the quantity/(x-direction beam size × y-direction beam size). Therefore, for correction, the allocation amount (modulation rate of the beam) V used to allocate to the pixel at coordinates (x, y+1) can be calculated by (x-direction beam size - (-x) direction offset amount) ×y direction offset/(x direction beam size×y direction beam size) to calculate.

In the example of Figure 10(a), the area ratio of the pixel offset to the coordinates (x-1, y-1) can be expressed as -x direction offset × -y direction offset/(x direction beam size × y-direction beam size) to calculate. Therefore, for correction, the allocation amount (modulation rate of the beam) W used to allocate to the pixel at coordinates (x+1, y+1) can be calculated by -x direction offset amount × -y direction offset amount/ (x-direction beam size × y-direction beam size) to calculate.

In the example of Figure 10(a), the area ratio of the pixel offset to the coordinates (x-1, y) can be offset in the -x direction × (y direction beam size - (-y) direction) Amount)/(x-direction beam size × y-direction beam size) to calculate. Therefore, for correction, the allocation amount (modulation rate of the beam) Z used to allocate to the pixel at coordinates (x+1, y) can be calculated by -x direction offset × (y direction beam size - (- y) direction offset)/(x direction beam size × y direction beam size) to calculate.

As a result, the modulation rate U of the beam of the pixels whose coordinates (x, y) are not assigned the remaining portion can be obtained by the 1-V-W-Z operation.

As described above, for the beam array unit, in other words, for each pixel 36 in the rectangular unit area 35 corresponding to one on the sample surface of the irradiation area 34, the modulation rate of the beam directed to the pixel and the resulting distribution are calculated. Go to the modulation rate of at least 1 surrounding pixel of the beam.

Then, the position shift correction unit 56 calculates, for each drawing path, for each pixel 36, the dose defined in the pixel multiplied by the modulation rate of the beam directed to the pixel. Furthermore, the position shift correction unit 56 calculates, for each drawing path, for each pixel 36, the dose defined in the pixel multiplied by the modulation rate of the beam directed to at least one surrounding pixel to be distributed. value. Then, the calculated value is assigned to the pixel where it is assigned. The position shift correction unit 56 calculates, for each drawing path, for each pixel 36 , a total value obtained by multiplying the dose defined in the pixel by the modulation rate of the beam directed to the pixel and the value allocated from other pixels. dosage. Thereby, a dose map for each drawing path in which the positional offset is corrected (a dose map after the positional offset is corrected for each path) can be created. The created dose map corrected for the positional offset of each path is stored in the memory device 144 .

The specifying unit 55 specifies, for each drawing path, the beam array unit, in other words, each pixel 36 in the rectangular unit area 35 corresponding to one on the sample surface of the irradiation area 34, which is irradiated with the ON defect beam that always contains it. The pixels of the excess dose defective beam are used as the defective beam position specifying process for each path (S120). Which beam irradiates the control grid 27 of each pixel 36 in the rectangular unit area 35 is determined based on the drawing order as described above.

The defect correction unit 60 performs correction for each drawing path so as to reduce the excess dose that becomes excessive due to the defective beam being irradiated in other drawing paths as a defective beam correction step (S122).

FIG. 11 is a diagram showing an example of defective beam correction according to Embodiment 1. FIG. FIG. 11(a) shows, for example, a case where four-path multi-drawing is performed (multiplicity = 4). In this case, for pixels that are not irradiated with the defective beam, for example, the dose in each drawing path is defined as the dose T(x) irradiated to each pixel divided by the number of drawing paths pass (here, 4) T(x)/pass. However, the pixels illuminated by the defective beam will form an excess dose if this continues. Therefore, the dose in the drawing path where the defective beam is irradiated cannot be controlled, so the dose in other drawing paths is corrected to the dose minus the excess dose Δ. In the example of FIG. 11(b) , the defective beam is irradiated on one drawing path among the four paths. In such a case, first, the excess portion Δ with respect to T(x)/pass is calculated. Then, for the remaining three drawing paths irradiated with the normal beam, the dose of Δ/3 is subtracted from the dose T(x)/pass of each.

FIG. 12 is a diagram showing another example of defective beam correction according to the first embodiment. There may be cases where the designed dose at the position to be irradiated with the defective beam is smaller than the excess dose Δ. In this case, it is difficult to correct the excess dose Δ only for this pixel. In such a case, the excess dose Δ or the excess portion that cannot be corrected in the pixel irradiated with the defective beam is distributed to the surrounding beams. Then, the defect correction unit 60 corrects the defect correction unit 60 by distributing, for each drawing path, the excess dose that becomes excessive due to the defective beam being irradiated on other drawing paths to the surrounding beams. As shown in FIG. 12 , excess portions that cannot be corrected are allocated to, for example, three irradiation positions 39 a , 39 c , and 39 g located around the irradiation position of the defective beam 11 . Each distribution amount is calculated so that the center of gravity of each distribution amount forms the irradiation position of the defective beam 11 . The calculated distributed dose can be corrected by subtracting the dose of the beam from the target irradiation position to correct the defective beam.

FIG. 13 is a diagram showing an example of the presence or absence of patterns in the processing area and the presence or absence of patterns for each main deflection area in the comparative example of Embodiment 1. FIG. FIG. 13(a) shows the presence or absence of a pattern in the processing area of one drawing path among the plural drawing paths of multi-drawing. Here, the case where the rectangular unit area 35 is used as the processing area is shown. In the example of FIG. 13(a) , the design pattern 12 is arranged in the rectangular unit area 35 . In addition, in this drawing path, the defective beam 11 is irradiated near the pattern 12 . When such a rectangular unit area 35 is drawn, the rectangular area 13 serving as the main deflection area is set for each tracking control as described above.

FIG. 13(b) shows, for example, a rectangular area 13a that becomes the main deflection area of the first tracking control. In the rectangular area 13a, for example, the first pixel row from the right of each sub-irradiation area 29 becomes the drawing target. The example in FIG. 13(b) shows a case where the defective beam 11 becomes such a target pixel.

FIG. 13(c) shows, for example, the rectangular area 13b that becomes the main deflection area of the second tracking control. In the rectangular area 13b, for example, the second pixel row from the right of each sub-irradiation area 29 becomes the drawing target. The example in FIG. 13(c) shows a case where the partial pattern 9a, which is a part of the pattern 12, becomes such a target pixel.

FIG. 13(d) shows, for example, a rectangular area 13c that becomes the main deflection area of the third tracking control. In the rectangular area 13c, for example, the third pixel row from the right of each sub-irradiation area 29 becomes the drawing target. The example in FIG. 13(d) shows a case where the partial pattern 9b of another part of the pattern 12 becomes such a target pixel.

Among the main deflection areas, the pattern is not arranged in the rectangular area 13a. Therefore, the drawing process of the rectangular area 13a is skipped. In this case, since the defective beam 11 is not irradiated, correction becomes unnecessary when performing defect correction on other drawing paths. Therefore, in Embodiment 1, the drawing process of the rectangular area 13a is controlled so that it is not skipped under certain conditions.

The limited dose determination unit 62 (dose determination unit) determines, for each drawing path and each processing area, whether there is an area near a predetermined defect position including a defective beam that forms an excess dose among the irradiated multiple beams 20 . The location of the dose that is defined as a non-zero value (a finite value).

FIG. 14 is a diagram showing an example of the presence or absence of patterns in the processing area and the presence or absence of patterns for each main deflection area in Embodiment 1. FIG. FIG. 14(a) shows the presence or absence of patterns in the processing area A of one drawing path among the plural drawing paths of multi-drawing. Here, the case where the rectangular unit area 35 is used as the processing area A is shown. In the example of FIG. 14(a) , the design pattern 12 is arranged in the rectangular unit area 35 similarly to FIG. 13(a) . Furthermore, the defective beam 11 is irradiated near the pattern 12 along this drawing path. Here, the limited dose determination unit 62 determines whether there is a position (pixel) at which a dose defining a non-zero value (limited value) exists in the region C including the vicinity of a predetermined defective position (defective pixel) to which the defective beam 11 is irradiated. . It is appropriate to assume that the correction area for correcting the positional shift of the pixel to be irradiated with the defective beam is the nearby area C. For example, a pixel area within a radius of several pixels centered on the pixel to be irradiated with the defective beam is considered appropriate. Alternatively, it is assumed that a pixel area within a radius of 1 to 2 beam size pitches centered on the pixel to be irradiated with the defective beam is ideal. Here, a rectangular area is shown as the nearby area C, but it is not limited to this. For example, even circular areas are suitable. Furthermore, an edge region B is set to take into consideration the defective beam in the processing region adjacent to the periphery of the processing region A. The edge width is appropriately set, for example, from a few pixels to a beam pitch of 1 to 2.

The limited dose determination unit 62 determines whether the defective beam 11 is located in the processing area A and whether there is a dose for which a designed non-zero value (limited value) is defined in the nearby area C. In this case, it is assumed that the dose of pixels with a defined non-zero value (limited value) in the nearby area C does not exceed the edge area B.

In the example of FIG. 14(a) , the defective beam 11 is located in the processing area A, and part of the pattern 12 is arranged in the nearby area C. Therefore, it is determined that there is a value that defines the design zero in the nearby area C ( finite value) dose of pixels. The pixels whose dose is defined as a non-zero value (limited value) in the nearby area C do not exceed the edge area B, so the premise is also problematic.

Therefore, the limited dose determination unit 62 determines that the pixel has a dose with a defined non-zero value (limited value). The dose of each pixel uses the value defined in the dose map stored in the memory device 144 . Here, it is appropriate to use the dose map corrected for the position offset of each path as the dose map.

The defect dose data generating unit 64 (defect position dose data generating unit) generates defect dose data in which a defect dose is defined at the defect position when a dose of a non-zero value (limited value) is defined in the nearby area C, as Defect dose data creation process (S132). In the example of FIG. 14(a) , dose data for defects is created at the position where the defective beam 11 is irradiated. For example, the maximum dose in each drawing path is set as the defect dose. The maximum dose in each drawing path may be the maximum dose using the dose of each pixel defined in the dose map (a dose map after position offset correction for each path).

The irradiation time calculation unit 66 calculates the irradiation time t corresponding to the dose of each pixel as an irradiation time calculation step (S142). The irradiation time t can be calculated by dividing the dose D by the current density J. The irradiation time t of each pixel 36 (control grid 27 ) is calculated as a value within the maximum irradiation time Ttr that can be irradiated by one shot of the multi-beam 20 . The irradiation time t of each pixel 36 (control grid 27) is converted into gradation value data of 0 to 1023 steps, with the maximum irradiation time Ttr being, for example, 1023 steps (10 bits). The hierarchical irradiation time database is stored in the memory device 142 .

The data processing unit 67 arranges the irradiation time data of each pixel in the order of the main deflection area and the order of emission for each drawing path as a data processing step (S144). The rectangular area 13 serving as the main deflection area is set for each tracking control caused by the tracking deflection. The example in FIG. 14(a) is part of an explanation of the case where the main deflection areas are arranged in order. FIG. 14(b) shows, for example, a rectangular area 13a that becomes the main deflection area of the first tracking control. In the rectangular area 13a, for example, the first pixel row from the right of each sub-irradiation area 29 becomes the drawing target. In the example of FIG. 14( b ), a case where the defective beam 11 becomes such a target pixel is shown. When the defect dose data is defined at the position of the defective beam 11, the state becomes the same as the state in which the defect pattern 17 is defined as shown in FIG. 14(b). FIG. 14(c) is the same as FIG. 13(c) , but for example, a rectangular area 13b serving as the main deflection area of the second tracking control is displayed. In the rectangular area 13b, for example, the second pixel row from the right of each sub-irradiation area 29 becomes the drawing target. In the example of FIG. 14(c) , as in FIG. 13(c) , the partial pattern 9 a that is part of the display pattern 12 becomes such a target pixel. In FIG. 14(d), similarly to FIG. 13(d), for example, a rectangular area 13c that becomes the main deflection area of the third tracking control is displayed. In the rectangular area 13c, for example, the third pixel column from the right of each sub-irradiation area 29 becomes the drawing target. In the example of FIG. 14(d) , similarly to FIG. 13(d) , the partial pattern 9 b of another part of the display pattern 12 becomes such a target pixel. Among these main deflection areas, the rectangular area 13a is changed from a state in which no pattern is arranged as shown in FIG. 13(b) to a state in which the defect pattern 17 is arranged as shown in FIG. 14(b).

As described above, the data for emission is divided into each main direction area.

The NULL determination unit 68 (pattern presence/absence determination unit) determines, for each rectangular area 13 on the surface of the sample 101 where the irradiation area 34 of the multi-beam 20 is set, the dose data at each position where the rectangular area 13 is scheduled to be irradiated. The presence or absence of the pattern in the rectangular area 13 is determined as the main deflection data NULL determination process (S146). The irradiation time data of the rectangular area 13 that becomes the main deflection area becomes the main deflection data. The state of no master bias data, that is, the state of no pattern, results in a situation where it is determined to be NULL (no pattern). Figure 14(b)~Figure 14(d) are all formed and judged as non-NULL (with pattern). In particular, even if the rectangular area 13 a to which the defective beam 11 is irradiated does not have a designed pattern, it is defined with dose data for defects, so that the drawing process is not skipped.

The drawing mechanism 150 skips the drawing process of the rectangular area 13 determined to be without a pattern, moves the rectangular area 13 to the next rectangular area 13 with a pattern, and corrects multiple drawings on other drawing paths. The sample 101 is patterned using the multiple beams 20 while the excess dose of any one of the drawing paths is caused by the defective beam 11 . In the example of FIG. 14 , for example, even if the defect correction is performed on the premise that the defective beam 11 is irradiated on the second drawing path in the first drawing path, the defect will be corrected in the second drawing path. , the defective beam 11 is irradiated without being skipped. Therefore, the defect correction in the first drawing path can be effectively performed. Similarly, for example, even if the defect correction is performed on the premise that the defective beam 11 is irradiated on the first drawing path in the second drawing path, the defective beam 11 will be irradiated in the first drawing path. Illuminate without being skipped. Therefore, the defect correction in the second drawing path can be effectively performed.

As described above, according to Embodiment 1, in multi-beam drawing, unnecessary defect correction can be avoided when the excess dose caused by the defective beam 11 is corrected across the drawing paths of the multi-beam drawing. Implementation form 2.

Embodiment 1 explains the case where, by creating dose data for defects at the irradiation position of the defective beam, it is determined that there is a pattern even in the rectangular area 13 without a pattern in the main deflection data NULL determination step (S146). In Embodiment 2, other configurations will be described. The structure of the drawing device of Embodiment 2 is the same as that of FIG. 1 . The flowchart showing the main steps of the drawing method in Embodiment 2 is the same as that shown in FIG. 8 . The following points are the same as those in Embodiment 1 unless otherwise specified.

In the main deflection data NULL determination step (S146) of Embodiment 2, the NULL determination unit 68 (pattern presence or absence determination unit) determines non-NULL (pattern presence) in each rectangular area 13 regardless of the presence or absence of a pattern. Other points are the same as in Embodiment 1.

In Embodiment 2, the defect vicinity limited dose determination step (S130) and the defect dose data creation step (S132) may be omitted. In such a case, the limited dose determination unit 62 and the defect dose data creation unit 64 may be omitted.

Thereby, although the skipped rectangular area 13 disappears, a state in which the defective beam 11 is not irradiated can be avoided. Therefore, all defect corrections can be made effective. Implementation form 3.

FIG. 15 is a flowchart showing the main steps of the drawing method according to Embodiment 3. FIG. 15 is the same as FIG. 8 except that the determination result of the main deflection data NULL determination process (S146) is stored in the storage device and the determination result of the main deflection data NULL determination process (S146) is fed back.

In addition, the structure of the drawing device of Embodiment 3 is the same as that of FIG. 1 . However, in the third embodiment, the limited dose determination unit 62 and the defect dose data creation unit 64 may be omitted. The following points that are not particularly described are the same as those in Embodiment 1.

In the third embodiment, the determination result in the main deflection data NULL determination process (S146) is stored in the storage device 144.

Therefore, in the defective beam correction step (S122), the defect correction unit 60 determines whether the second or subsequent drawing paths of the plural drawing paths of the multi-drawing are based on the main deflection data NULL for each rectangular area of the previous path. The determination result of the presence or absence of the pattern in the step (S146) determines whether to correct the excess dose caused by the defective beam 11 in this path. For example, whether the defective beam is irradiated in the first drawing path can be known from the determination result of the presence or absence of the pattern in the main deflection data NULL determination step (S146). Therefore, for example, based on the determination result in the second drawing path, defect correction is performed when the defective beam is irradiated on the first drawing path, and defect correction is not performed when the defective beam is not irradiated. This way, unnecessary bug fixes can be avoided. Implementation form 4.

FIG. 16 is a flowchart showing the main steps of the drawing method according to the fourth embodiment. In FIG. 16 , all steps of the drawing path from the beam position deviation measurement step (S102) to the main deflection data NULL determination step (S146) are used as the drawing processing before starting the first drawing path. Except for the pre-processing points, it is the same as in Figure 15. Therefore, the point where the determination result of the main deflection data NULL determination step (S146) is stored in the storage device 144 and the point where the determination result of the main deflection data NULL determination step (S146) is fed back is the same as in Embodiment 3.

In addition, the structure of the drawing device of Embodiment 4 is the same as that of FIG. 1 . However, in the fourth embodiment, the limited dose determination unit 62 and the defect dose data creation unit 64 may be omitted. The following points that are not particularly described are the same as those in Embodiment 1.

In Embodiment 4, all steps of the drawing path from the beam position deviation measurement step (S102) to the main deflection data NULL determination step (S146) are performed before starting the drawing process of the first drawing path. pre-processing. Therefore, the determination of the presence or absence of the pattern for each rectangular area 13 is performed as preprocessing before starting the drawing process.

Thereby, in the defective beam correction step (S122), the defect correction unit 60 determines for each drawing path, and whether the defective beam is irradiated in other drawing paths is based on the pattern in the main deflection data NULL judgment step (S146). The judgment result of whether or not is known. Therefore, the defect correction unit 60 determines whether to correct the excess dose caused by the defective beam 11 in the path using the determination result of the presence or absence of the pattern in the main deflection data NULL determination step (S146). In Embodiment 4, before starting the drawing process of the first drawing path, the judgment results of the presence or absence of patterns in the main deflection data NULL judgment step (S146) of all drawing paths are complete. Therefore, Embodiment 4 can further determine whether the defective beam is irradiated on the drawing path performed later. Therefore, for example, in the first drawing path, it can be determined whether to perform correction of the predetermined defective beam irradiated in the second drawing path. Implementation form 5.

FIG. 17 is a conceptual diagram showing the structure of a drawing device according to Embodiment 5. FIG. In FIG. 17 , the control computer 110 is the same as in FIG. 1 except that the determination unit 61 is added. Rasterization unit 50, dose data creation unit 52, beam position deviation map creation unit 54, position deviation correction unit 56, detection unit 57, identification unit 58, defect correction unit 60, determination unit 61, limited dose determination Each "~ section" including the unit 62, the defect dose data creation unit 64, the irradiation time calculation unit 66, the data processing unit 67, the NULL determination unit 68, and the drawing control unit 74 has a processing circuit. Such processing circuits include, for example, electrical circuits, computers, processors, circuit substrates, quantum circuits or semiconductor devices. Each "~ section" may use a common processing circuit (same processing circuit), or may use different processing circuits (separate processing circuits). It is input to the rasterization unit 50, the dose data creation unit 52, the beam position deviation map creation unit 54, the position deviation correction unit 56, the detection unit 57, the identification unit 58, the defect correction unit 60, and the determination unit 61 , the information of the limited dose determination unit 62 , the defect dose data creation unit 64 , the irradiation time calculation unit 66 , the data processing unit 67 , the NULL determination unit 68 and the drawing control unit 74 and the information being calculated are stored in the memory 112 each time .

FIG. 18 is a flowchart showing the main steps of the drawing method according to the fifth embodiment. 17 is the same as FIG. 8 except that the determination process (S128) is added before the defect vicinity limited dose determination process (S130).

In addition, the following content is the same as that of Embodiment 1 except for the points specifically explained.

Beam position shift amount measurement process (S102), defective beam detection process (S104), dose calculation process (S110), position shift correction process for each path (S112), defective beam position identification process for each path The contents of each step (S120) and the defective beam correction step (S122) are the same as those in the first embodiment.

As the determination step (S128), the determination unit 61 determines whether the size of the area in which only the dose of zero is defined is equal to or less than a critical value. Specifically, the determination unit 61 refers to the positional deviation corrected dose data for each path and determines whether the size of the area where only zero dose is defined is 1/n or n times or less of the rectangular area. n is a natural number. If the size of the area in which only zero dose is defined is not equal to or smaller than the critical value, the process proceeds to the defect vicinity limited dose determination process (S130). If the size of the area where only zero dose is defined is less than the critical value, the defect vicinity limited dose determination process (S130) and the defect dose data creation process (S132) are skipped, and the process proceeds to the irradiation time calculation process (S142). In other words, the defect vicinity limited dose determination process (S130) and the defect dose data creation process (S132) are performed only for a patternless area of a certain size.

The contents of each step after the defect vicinity limited dose determination step (S130) are the same as those in the first embodiment. In addition, when the defect vicinity limited dose determination process (S130) and the defect dose data creation process (S132) are skipped, the main deflection data NULL determination process (S146) is configured to always determine non-NULL (patterned). as appropriate.

As mentioned above, the drawing process time can be shortened by skipping a small area among the non-pattern areas.

The embodiments have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. The above example explains the case where the irradiation time of each beam of the multi-beam 20 is controlled individually for each beam within the maximum irradiation time Ttr of one shot. However, it is not limited to this. For example, the maximum irradiation time Ttr of one shot is divided into a plurality of sub-shots having different irradiation times. Then, for each beam, a combination of sub-emissions is selected from a plurality of sub-emissions so as to form an irradiation time of one shot. Then, it is also appropriate to control the irradiation time of one emission part for each beam by continuously irradiating the same pixel with the same beam for the selected combination of sub-emissions.

In addition, the above example shows a case where a 10-bit control signal is input to each control circuit 41 for control, but the number of bits may be set appropriately. For example, a 2-bit or 3-bit to 9-bit control signal may also be used. In addition, control signals of more than 11 bits can also be used.

In addition, descriptions of parts such as device configuration and control techniques that are not directly necessary for the description of the present invention are omitted, but necessary device configurations and control techniques can be appropriately selected and used. For example, the description of the control unit configuration for controlling the drawing device 100 is omitted, but it is of course necessary to appropriately select and use the necessary control unit configuration.

In addition, all multi-charged particle beam imaging devices and multi-charged particle beam imaging methods that have the elements of the present invention and can be appropriately designed and modified by the industry are included in the scope of the present invention.

9: Partial pattern 11:Defect bundle 12:Pattern 13: Rectangular area 20:Multiple beams 22:hole 24:Control electrode 25:Through hole 26:Counter electrode 27:Control grid 28:pixel 29: Sub-irradiation area 30: Draw area 32: Strip area 31:Substrate 33:Support platform 34:Irradiation area 35: Rectangular unit area 36: pixels 39: Irradiation position 41:Control circuit 50: Rasterization Department 52:Dose data creation department 54: Beam position offset map creation department 56:Position offset correction part 57: Measurement part 58:Special Department 60:Defect Correction Department 61:Judgment Department 62:Limited dose determination department 64: Defect dose data creation department 66:Irradiation time calculation part 67:Data Processing Department 68: NULL judgment part 74:Description Control Department 100:Depicting device 101:Sample 102: Electronic lens tube 103:Description room 105:XY platform 106: Faraday Cup 110: Control computer 112:Memory 130: Bias control circuit 132,134,136: DAC amplifier unit 139: Platform position detector 140,142,144:Memory device 150: Depicting institutions 160: Control circuit 200:Electron beam 201:Electron gun 202:Lighting lens 203: Shaped aperture array substrate 204: Blanking aperture array mechanism 205: Magnifying lens 206: Restricted aperture substrate 207:Object lens 208,209: deflector 210:Reflector 212:Total blanking deflector 330:Thin film area 332:Peripheral area

[Fig. 1] is a conceptual diagram showing the structure of the drawing device according to Embodiment 1. [Fig. [Fig. 2] is a conceptual diagram showing the structure of the molded aperture array substrate according to Embodiment 1. [Fig. [Fig. 3] is a cross-sectional view showing the structure of the blanking aperture array mechanism according to the first embodiment. [Fig. 4] is a conceptual diagram for explaining an example of the drawing operation in Embodiment 1. [Fig. FIG. 5 is a diagram showing an example of a multi-beam irradiation area and drawing target pixels according to Embodiment 1. [Fig. 6] Fig. 6 is a diagram for explaining an example of the multi-beam drawing method according to the first embodiment. [Fig. 7] Fig. 7 is a diagram showing an example of the presence or absence of patterns in each drawing path in Embodiment 1. [Fig. 8] is a flowchart showing the main steps of the drawing method according to Embodiment 1. [Fig. [Fig. 9(a)(b)] are diagrams for explaining the position shift and position shift periodicity of the beam in Embodiment 1. [Fig. 10(a)(b)] are diagrams for explaining an example of the position offset correction method according to the first embodiment. [Fig. 11(a)(b)] are diagrams showing an example of defective beam correction according to Embodiment 1. [Fig. 12] Fig. 12 is a diagram showing another example of defective beam correction according to the first embodiment. [Figs. 13 (a) to (d)] are diagrams showing an example of the presence or absence of patterns in the processing area and the presence or absence of patterns for each main deflection area in the comparative example of Embodiment 1. [Figs. 14 (a) to (d)] are diagrams showing an example of the presence or absence of patterns in the processing area and the presence or absence of patterns for each main deflection area in Embodiment 1. [Fig. 15] is a flowchart showing the main steps of the drawing method according to Embodiment 3. [Fig. [Fig. 16] is a flowchart showing the main steps of the drawing method according to the fourth embodiment. [Fig. 17] is a conceptual diagram showing the structure of a drawing device according to Embodiment 5. [Fig. [Fig. 18] is a flowchart showing the main steps of the drawing method according to the fifth embodiment.

20:Multiple beams

50: Rasterization Department

52:Dose data creation department

54: Beam position offset map creation department

56:Position offset correction part

57: Measurement part

58:Special Department

60:Defect Correction Department

62: Limited dose determination department

64: Defect dose data creation department

66:Irradiation time calculation part

67:Data Processing Department

68:NULL judgment part

74:Description Control Department

100:Depicting device

101:Sample

102: Electronic lens tube

103:Description room

105:XY platform

106: Faraday Cup

110: Control computer

112:Memory

130: Bias control circuit

132,134,136: DAC amplifier unit

139: Platform position detector

140:Description information

142: Irradiation time data of each emission

144:Position offset data

150: Depicting institutions

160: Control circuit

200:Electron beam

201:Electron gun

202:Lighting lens

203: Shaped aperture array substrate

204: Blanking aperture array mechanism

205: Magnifying lens

206: Restricted aperture substrate

207:Object lens

208,209: deflector

210:Reflector

212:Total blanking deflector

Claims (7)

A multi-charged particle beam mapping device, which is characterized by: A beam forming mechanism that forms a multi-charged particle beam; a dose data generating unit that generates dose data defining individual doses for each position within the treatment area for each of a plurality of treatment areas divided by the drawing area on the sample surface; A dose determination unit that determines, for each of the aforementioned processing areas, whether there is a dose defined as a non-zero value in an area near a predetermined defect position including a defective beam that is irradiated with the multi-charged particle beam and forms an excess dose. location; a defect position dose data generating unit that generates defect dose data in which a defect dose is defined at the defect position when a dose of a non-zero value is defined in the nearby area; A pattern presence/absence determination unit determines, for each unit area on the sample surface where the irradiation area of the multi-charged particle beam is set, the dose data at each position scheduled for irradiation in the unit area. the presence or absence of patterns; and A drawing mechanism that uses the multi-charged particle beam to skip the unit area judged as having no pattern by the pattern presence/absence judgment unit when drawing a pattern on the sample, and causes the unit area to be drawn to be judged next. The patterned unit area is moved, and the excess dose caused by the defective beam in any one of the plurality of drawing paths of the multiple drawing is corrected so that it is reduced in the other drawing paths. The multi-charged particle beam imaging device as described in claim 1, further comprising: A movable platform for carrying the aforementioned samples; and a tracking deflector that performs tracking deflection of the multi-charged particle beam in such a way that the irradiation area of the multi-charged particle beam follows the movement of the platform, The aforementioned unit area is set for each tracking control caused by the aforementioned tracking bias. The multi-charged particle beam drawing apparatus according to claim 1 or 2, wherein the pattern presence or absence determining unit determines that the pattern is present in each unit area. The multi-charged particle beam drawing apparatus according to claim 1 or 2, further comprising: a memory device that stores the determination result of the presence or absence of the pattern per unit area, In the second and subsequent drawing paths of the plurality of drawing paths in the multi-drawing, it is determined whether or not to correct the excess dose caused by the defective beam in this path based on the determination result of the presence or absence of a pattern per unit area in the preceding path. The multi-charged particle beam drawing apparatus according to claim 1 or 2, wherein the determination of the presence or absence of the pattern per unit area is performed as a preprocessing before starting the drawing process. A multi-charged particle beam depiction method, which is characterized by: The process of forming a multi-charged particle beam; A process of generating dose data defining individual doses for each position within the treatment area for each of a plurality of treatment areas divided by a drawing area on the sample surface; A process of determining, for each of the aforementioned processing areas, whether there is a location where a dose defining a non-zero value exists in an area including a predetermined defect location that is irradiated with the multi-charged particle beam and forms a defective beam with an excess dose; A process of generating defect dose data in which a defect dose is defined at the defect position when a dose with a non-zero value is defined in the nearby area; A step of determining, for each unit area on the sample surface where the irradiation area of the multi-charged particle beam is set, the presence or absence of a pattern in the unit area using dose data at each position scheduled for irradiation of the unit area; and The multi-charged particle beam is used to draw a pattern on the sample. When performing the drawing, the unit area judged to be without a pattern is skipped, and the unit area to be drawn is moved to the next unit area judged to be patterned. The excess dose caused by the defective beam in any one of the plural drawing paths of the multi-drawing is corrected to be reduced in other drawing paths. The multi-charged particle beam imaging method according to claim 6, further comprising: performing a tracking direction of the multi-charged particle beam so that the irradiation area of the multi-charged particle beam can follow the movement of the movable platform on which the sample is placed. the process, The aforementioned unit area is set for each tracking control caused by the aforementioned tracking bias.

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